   4. separate transformation data-group columns from the others"
   [{:keys [tenant-conn] :as deps}
    {:keys [transformation data-groups data-group]}]
-  (let [data-group (or data-group (data-group-by-tx transformation data-groups))
+  (let [data-group (or data-group (data-group-by-op transformation data-groups))
         source-table (:table-name data-group)
         other-dgs-columns (reduce (fn [c dg] (if (= (:id dg) (:id data-group))
                                                c (into c (:columns dg)))) [] data-groups)

    (if-let [transformation (first transformations)]
      (let [columns (reduce into [] (map :columns data-groups))
            transformation       (adapt-transformation transformation old-columns columns)
            data-group (data-group-by-tx transformation data-groups)
            avoid-tranformation? (let [t (w/keywordize-keys transformation)]
                                   (and
                                    (avoidable-if-missing? t)

    (throw (ex-info "Failed to transform. Transformation can't have columns from more than one data-group specified"
                    {:transformation transformation}))))

(defn data-group-by-op [transformation data-groups]
  (let [columns-in-transformation (columns-used (w/keywordize-keys transformation) (reduce into [] (map :columns data-groups)))
        _  (ensure-one-data-group-related transformation columns-in-transformation data-groups)
        column-name (first columns-in-transformation)]
